Jewelry clasp, particularly for earrings

ABSTRACT

An elongated semi-product from which a clasp can be formed includes at each end at least one through-penetrating hole wherein when bent to form said clasp the semi-product forms a generally closed cavity with the mutually opposite ends of said product forming overlapping legs and the openings at the ends of said semi-product being intended to coincide in one position of the legs to enable said stem-part to be inserted easily through the two holes in said legs, wherein in another position of said legs the holes provided in the edge regions of the ends of said legs will be pressed against a portion of reduced diameter on the stem so as to hold an ornament in place. According to the invention, at least one of the two opposing openings in the semi-product has an elongated and irregular shape so as to include at least two holes of different sizes, and at least one opening extends transversely to the longitudinal axis of the semi-product.

The present invention relates to an elongated, plate-like semi-productwhich has a certain degree of springless and from which there isproduced a jewelry clasp for securing a piece of jewelry comprising anornamental object and a stem, such as an earring, an eardrop or a broachfor instance, wherein the stem or tang is intended to coact lockinglywith the clasp. The elongated semi-product includes at least onethrough-penetrating opening at each end thereof, or in the proximity ofeach end thereof, and is intended to be bent in a manner to definemutually overlapping legs such that the holes at the ends of said legswill be in register with one another in one position of said legs andtherewith enable the stem to be inserted easily through said openings,and such that the surfaces defining said holes will be pressed against astem portion of smaller cross-section in another position of the legsand therewith lock the clasp to the stem.

BACKGROUND OF THE INVENTION

Ear-carried ornaments or jewelry, for instance earrings, or eardrops,can be secured in several different ways. For instance, the jewelry canbe secured to the wearer's earlobe with the aid of a clip which clampsthe jewelry to the earlobe. When the jewelry or ornament concernedincludes a stem or tang of round cross-section, the earlobes will bepierced and the stem inserted through the hole and appropriatelysecured. The clasp, or like locking device, is then located behind theearlobe, with the ornament or jewel seated against or hanging from thefront part of the earlobe.

DESCRIPTION OF THE PRIOR ART

With regard to this latter category of ear-carried ornaments, part ofthe stem of the ornament is screw-threaded for coaction with a lockingnut which, when fitted, lies against the rear side of the earlobe andprevents the stem from sliding unintentionally from the pierced hole inthe earlobe. Another and more frequently used clasp design isillustrated in FIG. 1 of the accompanying drawings. An initiallyelongated, plate-like piece of material includes a center hole 10 andits two mutually opposite ends have been bent to form mutually oppositecurved legs 11, 12. After having formed the legs of the clasp, the hole10 will be located centrally therebetween. The ornament, or jewel, isreferenced 13' in the Figure and includes a stem 13 which is insertedthrough a hole pierced in the earlobe of the wearer. The stem 13includes a part of smaller cross-section, i.e. a reduced part 14 againstwhich the extremities of the legs 11, 12 are pressed into frictionalengagement. It will be understood that the legs 11, 12 have a givenspringiness. This known clasp design, has obvious drawbacks. As thematerial from which the clasp is made becomes fatigued, the frictionalengagement between the stem and the rounded abutment surfaces of theclasp will decrease. This fatigue of the material caused by repeated useof the clasp cannot be controlled by the user, and when the strength ofsaid frictional engagement is reduced, the stem is liable to slide outof the clasp. Another drawback with the clasp illustrated in FIG. 1resides in the compromise that is made with regard to the fact that thelocking friction between the legs must not be excessively large, whileenabling the ornament to be fastened in and released from the ear bygripping the ornamental part of the earring with the fingers of one handand moving the stem into and out of the pierced hole while manipulatingthe clasp with the other hand. The clasp is also small and is thus ableto slip from the hand of the wearer when releasing the clasp, with therisk of being lost.

A similar clasp is disclosed in DE-C-30 09 607. FIGS. 4, 5 of thisearlier publication illustrate an elongated, plate-like semi-producthaving a circular opening at or in the proximity of each end-partthereof. The semi-product is bent to form two legs which overlap oneanother in the longitudinal direction of the semi-product, wherein theholes and the ends of the legs can be brought into alignment with oneanother by exerting a force in the longitudinal direction of thesemi-product, so as to enable the stem of an ear-carried ornament to beinserted into a hole pierced in the earlobe of the wearer. As this forceis released, the legs spring away from one another (or at least one legsprings away from the other) so as to mechanically lock the stem. Aswith the aforementioned known clasp design, this latter clasp has thedrawback of being brought to an operative state by the application ofpressure in the "spring" direction of the locking element, i.e. in thelongitudinal direction of the semi-product, and that locking is effectedsolely against one side of the reduced stem-portion and against itsconical junction with the remainder of the stem. Thus, it is thespringiness of the material that determines the long-term functioning ofthe clasp, in combination with the size of the contact surface areabetween the reduced part of the stem and the hole-defining surfaces. Themore springy the material, the better the mechanical locking of thestem, because the defining edge of the mutually opposite holes oropenings will act with an oppositely acting spring force against thereduced part of said stem. These contact surfaces are very small inarea, however, and gradual impairment of the springless of said materialwill increase the risk of impairment of the mechanical locking effectearlier achieved, or in part. In practice, only one of the two legs isspringy in the aforesaid concept. It will also be remembered that aclasp a locking device of this kind has very small dimensions. Forinstance, the semi-product from which the clasp is formed may have alength of only some 13 mm. When an ornament is attached to the ear ofthe wearer, the clasp is, in principle, secured by touch and feel alone.The following features are required of a clasp for ear-carriedornaments:

a) It must be possible to guide the stem of the ornament easily intocoaction with the clasp.

b) Despite the small dimensions of the clasp, the user must be able togrip the clasp firmly and reduce or eliminate the risk of the clasp"flipping" from the user's grip and being lost.

c) The spring force inherent in the clasp must be highly durable. Thisis achieved when the spring force is only required to return the leg orlegs of the clasp to its/their rest position (locking position) and notto lock the clasp to the stem.

d) The contact surface between the reduced part of the stem and thehole-defining surfaces is optimal in ensuring positive and reliablemechanical locking of the clasp.

Taking as its starting point the points discussed above and thejewelry-clasp semi-product known particularly from DE-C-30 09 607, whichis considered to represent the most relevant prior art, the presentinvention provides a semi-product of the aforedescribed kind which ischaracterized by the features set forth in the characterizing clause ofthe following claim 1. The invention also relates to a clasp or lockingdevice formed from such a semi-product.

So that the invention will be more readily understood and furtherfeatures thereof made apparent, the invention will now be described withreference to an exemplifying embodiment thereof and also with referenceto the accompanying drawings, in which

FIG. 1 is a perspective view of a known clasp and illustrates itscoaction with a circular stem or tang whose one end is connected to anornamental object, for instance a pearl;

FIG. 2a illustrates a first preferred embodiment of an inventive claspsemi-product;

FIG. 2b illustrates a modified form of the semi-product shown in FIG.2a;

FIG. 3 shown the semi-product of FIG. 2a bent into the form of a clasp,said clasp being shown in a first position, a rest position; and

FIG. 4 shows the clasp arrangement of FIG. 3 with the legs of said claspbeing brought by means of oppositely directed forces to a position inwhich the openings in the legs are principly in register with oneanother and with a centrally located reduced portion of the stem.

The known technique illustrated in FIG. 1 has already been describedabove.

Illustrated in FIG. 2a is a referred embodiment of an elongated andplate-like semi-product 20 from which the improved, inventive jewelryclasp can be produced. The semi-product 20 is preferably comprised of aprecious metal, for instance gold, although other, particularlymetallic, materials can be used. The semi-product 20 has two mutuallyopposing, widened end-parts 21 and 22, each of which merges with arespective web part 23 and 24, which in turn merge with a widenedcenter-part 25 which includes guide means in the form of athrough-penetrating opening or a blind hole 26 having a conical lead-inand functioning a s a stem guide. When seen in the plane of the drawing,each of the widened end-parts of the semi-product has a respectiveangled lip 27 and 28 which extends around a part of the perimeter, orperiphery, of its respective widened part 21, 22 and define an angle ofabout 90° therewith. As will be seen from the drawings, the upper lip 27is placed on the left side of its widened part 21, whereas the lower lip28 is placed on the right side of the widened part 22. Each widenedend-part 21 and 22 has a respective through-penetrating opening 29 and30. In the FIG. 2a embodiment, which is the preferred embodiment, oneend-part 22 of the semi-product 20 has a central, circular opening 30,whereas the opening 29 in the opposite end-part 21 is an irregular,elongated opening which extends transversely to the longitudinal axis ofthe semi-product 20. By "elongated, irregular" is meant that the opening29 has a form such as to include at least two holes of mutuallydifferent sizes, i.e. one relatively small hole and one larger hole.Examples of such irregular shapes are pear shapes, keyhole shapes oroval shapes. The openings 29, 30 of the preferred embodiment have akeyhole shape. FIG. 2a shows a geometric axis A which extends betweenthe round hole 30 in the lower end of the semi-product shown in FIG. 2a,and the center of the upper, elongated opening 29, namely the hole ofgreater diameter, while passing through the center hole 26. Also shownis a geometric axis B which extends from the center hole 26 to thecenter of the hole of smaller diameter in the elongated opening 29.

FIG. 2b illustrates the case when the openings 29, 30 at respective endsof the semi-product are identical with one another, in the illustratedcase a keyhole shape although the holes may equally as well have a pearshape or an oval shape. In the illustrated case, the elongated openings29, 30 extend transversely to the longitudinal axis of the semi-product20 and are mirror images of one another. In the illustrated case, thegeometric axis A connects the centra A'--A' of the holes of largerdiameter in respective elongated openings 29, 30. The broken line axis Bconnects the centra B'--B' of respective holes of smaller diameter insaid elongated openings 29, 30. The axes A and B intersect one anotherat the center of the semi-product 20, i.e. in the center of the blindhole or the through-penetrating opening 26.

Referring back to FIG. 2a, the larger hole in the opening 29 in thewidend end-part 21 and the round opening 20 in the widened end-part 22are dimensioned to enable the stem or tang (not shown) of a piece ofjewelry (also not shown) to be easily inserted, while the smaller holein the opening 29 is dimensioned to tightly embrace at least the reducedportion of the stem and to provide optimal abutment surfaces therewith.

The clasp, or like locking device, is formed by bending the semi-product20 shown in FIGS. 2a and 2b in a plane such that the widened end-partswill partially overlap one another. In other words, the semi-product 20is bent in a plane which forms a right angle α with the axis B.

Bending of the semi-product 20 shown in FIG. 2a in this manner willresult in a clasp of the configuration shown in FIG. 2. As will be seen,after bending the semi-product 20 in the aforedescribed manner, the legs21 and 22 formed by the opposing end-parts of said product 20 will bedisplaced relative to one another in the transverse direction of theproduct 20, i.e. will partially overlap one another with the leg 22having the transversely extending larger hole positioned beneath the leg21 which has the single round hole 29. (The reverse position may also beapplied.) The opening 50 defined in this position of the legs 21, 22 hasa size which corresponds approximately to the diameter of the reducedpart 14 of the stem (see FIG. 1). FIG. 3 thus illustrates thestem-securing state of the clasp, which is also the state in which thelegs 21, 22 constantly strive to return to their original position as aresult of the torsional forces acting thereon. The opening 50 is thusdefined by both the round hole 30 of the one leg 22 and by the smallerhole in the elongated opening 29 of the other leg 21. FIG. 4 shown thatthe legs 21, 22 can be pressed together (the force arrows P1, P2),wherein the downwardly directed lips 27 and 28 function to guide thelegs so that the holes 29, 30 in respective legs 21, 22 will coincidesuch that the round hole 30 in the leg 22 will be in register with thelarger hole in the keyhole opening 29, which therewith defines anoptimal opening that will enable the stem or tang of a piece of jewelryto be easily inserted into or removed from the clasp. The stiffnessafforded by the lips 27, 28 makes relative lateral displacement of thelegs impossible.

The inventive clasp affords the following advantages:

a) The locking effect afforded by the clasp is highly effective, due tothe fact that the hole-defining surfaces are in contact with both sidesof the reduced stem portion.

b) The "hole" that is formed by the openings 29, 30 when a stem or tangis to be inserted is maximally large, i.e. much larger than the diameterof the stem.

c) Because at least one of the openings 29, 30 extends transversely tothe longitudinal axis of the semi-product, the legs 21, 22 are subjectedto a force which acts transversely to the longitudinal axis of thesemi-product, which is also its main "spring" direction.

d) The springiness of the semi-product 20 will not become dissipated,because this spring force is not used to lock the clasp.

The angled lips 27 and 28 function to guide the legs 21, 22 so that theopenings 29, 30 will always be brought into appropriate alignment withone another in the aforesaid manner, and also function as abutments in aposition in which optimal alignment of respective holes in the opening29, 30 is achieved.

USE AND FUNCTION

When securing an ear-carried ornament with the aid of the novel clasp,the stem or tang of the ornament is first inserted through a holepierced in an earlobe, for instance. That part of the stem which thenprojects out from behind the ear is inserted into the central hole 26 ofthe inventive clasp while, at the same time, exerting said force P1 andP2 on respective opposite legs so as to bring the openings 29 and 30into mutual alignment and allow the stem to pass unhinderedtherethrough. The forces P1 and P2 are then relaxed, so that the reducedportion of the stem will be guided into the smaller hole of theelongated opening 29 and the clasp brought to the state shown in FIG. 3.The size of this latter opening is only insignificantly larger than thediameter of the reduced stem-portion, which means that the reducedstem-portion will abut three side-edges of the hole, therewithpreventing the stem from moving axially in the hole and providing aneffective mechanical locking effect. It will be seen that the guide lipsof the inventive clasp arrangement contribute towards ensuring that theopenings and holes 26, 29 and 30 will always be brought into mutualalignment when the aforesaid forces P1 and P2 are applied.

Although the invention has been described and illustrated with referenceto a preferred embodiment thereof, it will be understood that thesemi-product on which the novel clasp arrangement is based may be formedin a number of other ways. As before mentioned, the widened end-parts ofthe semi-product 20 may have a form other than round, for instance apolygonal form. At least one of the openings 29, 30 shall have a formwhich will provide holes of mutually different sizes.

Although the clasp has been described mainly with reference toear-carried ornaments, such as earrings, eardrops and the like, it willbe understood that the inventive clasp can also be used to fastenjewelry or ornaments to other facial features, such as the nose or lipsfor instance, when feasible.

It will also be understood that the invention is not restricted to theillustrated and described embodiments thereof and that modifications andchanges can be made within the scope of the inventive concept as definedin the following claims.

I claim:
 1. An elongated, plate-like semi-product (20) from which therecan be formed a clasp or like locking device for holding in place apiece of jewelry comprising an ornamental part and a stem-part, wherethe stem portion is intended to coact with the clasp, wherein thesemi-product (20) includes at each end or in the proximity of said endsat least one through-penetrating hole (29, 30), of which at least one(29) hole has an elongated and irregular shape so as to include at leasttwo holes of different sizes, wherein when bent to form said clasp thesemi-product (20) forms a generally closed cavity with the mutuallyopposite ends of said product (20) forming overlapping legs (21, 22) andthe openings (29, 30) at the ends of said overlapping legs beingintended to coincide in one position of the legs so as to enable saidstem-part to be inserted easily through the two holes in said legs,wherein in another position of said legs the holes provided in the edgeregions of the ends of said legs will be pressed against a portion ofreduced diameter on the stem so as to hold the stem, and therewith theornament, in place, characterized in that said at least one opening (29)extends transversely to the longitudinal axis of the semi-product (20)and, when the semi-product is bent in a known manner to form twomutually overlapping legs (21, 22), the step-part (24) can be insertedthrough both openings (29, 30) upon application of counter-directionalforces on the legs (21, 22) transversely to their longitudinaldirection, wherein release of said forces will cause the openings to bedisplaced relative to one another and away from each other to define aposition in which the reduced stem-part coacts with the edges of themutually opposing openings (29, 30) in said legs, wherein the mutuallyopposing ends of the product have a round shape, and merge with arelatively narrow web portion; and that each end of the semi-productincludes a generally right-angled lip or collar (27, 28) which extendsaround at least a part of the periphery of its respective end.
 2. Asemi-product for producing a jewelry clasp in accordance with claim 1,characterized in that the leg (21) of the semi-product (20) that hassaid elongated and irregular opening which includes at least two holesof mutually different size is the bottom leg of the at least partiallyoverlapping legs (21, 22).
 3. A semi-product for producing a jewelryclasp in accordance with claim 2, characterized in that the other leg(22) of said mutually opposing legs (21, 22) has an opening (30) ofcircular or essentially circular shape.
 4. A semi-product for producinga jewelry clasp in accordance with claim 1, characterized in that theopenings in the two mutually opposing legs (21, 22) are identical orgenerally identical and have an elongated, irregular shape so as to bothinclude two holes of mutually different sizes, wherein after bending thesemi-product to define at least partially overlapping legs, the holes oropenings (29, 30) will be mirror images of each other in thelongitudinal direction of the semi-product.
 5. A semi-product forproducing a jewelry clasp in accordance with claims 1-4, characterizedin that the elongated irregular opening or openings has/have a pear orkeyhole configuration.
 6. A method of bending an elongated semi-productto form a jewelry clasp and with the intention of forming at leastpartially overlapping lets, characterized by bending a semi-product ofclaim 1 in a plane in which an imaginary line extends between thecentral hole (21) of said semi-product (20) and the hole of smallerdiameter in the elongated opening at the end of one leg forms a rightangle with a bending plane.
 7. A jewelry clasp produced in accordancewith the method of claim 6.